class_docstr: Tag object associated with an experiment.
docstr: String name of the tag.
docstr_tok: ["String","name","of","the","tag","."]
code: def key(self):
      """String name of the tag."""
      return self._key
  
file_path: mlflow/mlflow/entities/experiment_tag.py
imports: from mlflow.entities._mlflow_object import _MLflowObject
  from mlflow.protos.service_pb2 import ExperimentTag
label_desc: Use image node_id 3 for calling the ExperimentTag obj's underlying member method code with example usage: obj.key() and returns: self